It is something almost mathematical: We go to the supermarket, we look for the shelf where the eggs are, we take an egg cup, we check that everything is fine, and we put it in the basket. Then, when we get home, directly (without thinking twice) we put the eggs in the fridge.
We do it automatically, but if we analyze the process, a disturbing question may arise: why do we keep them in the fridge if they are always left out in the supermarket? Or why don't they put them in the supermarket inside the fridges? ?
To solve the mystery, we have asked Luis Riera, director of SAIA - food and water safety consultancy -, who explains the reason.
"The cuticle, that is, that thin layer that surrounds the egg below the shell, can break with a sudden change in temperature," explains the expert. Which would be a great risk to our health, because that thin layer is what protects the egg from salmonella that it may contain in its shell. "If we keep taking the eggs in and out of the fridge, that natural protection could be lost."
Contraction or expansion due to cold and heat would displace the cuticle, hence the ideal is not to refrigerate the eggs before they reach the refrigerators in our homes.
“The egg, as long as the cuticle is intact, is quite sterile. It doesn't matter if you keep it cold or hot as long as it hasn't been more than 28 days, which is the time it takes to age”, says Riera.
For those who are in the habit of washing the eggs before storing them (although they are few, surely there are), the expert says that it is a big mistake, because the pressure of the water could break the cuticle. "Before using them, they can be washed, but only before consumption, because it does not give time for salmonella to enter."
Why do we keep them in the fridge at home?
Leaving them in the fridge when we get home also responds to a reason: "The air takes longer to enter and the egg is more concentrated when it is boiled or fried," says Riera. In other words, the fridge helps the egg keep a denser white and a more centered yolk.
The funny thing is that if it has been in or out of the fridge it does not influence when mixing, "for this type of preparation it does not matter if it is fresher or less".
How to detect its degree of freshness?
Riera says that there is an old and infallible trick to know if an egg is fresh or not: “Put it in a glass of water. If it sinks, it means that a short time has passed, it has little air and it is fresh. If, on the contrary, it floats, it means that it is an old egg, because a lot of air has entered it.
Of course, be careful, that it is an old egg does not mean that it cannot be eaten. Although unfortunately to detect if it is bad or not, there are no tricks.
